Cenozoic

Cretaceous

Neoproterozoic

Information provided by geoscience team at Ahmadu Bello University, Zaria, Nigeria --see About

Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple

Zurak Formation

Zurak Fm

Period:

Cretaceous

Age Interval:

Cenomanian-Turonian

Province:
Benue Trough Central

Type Locality and Naming

Not yet given.

References: Reyment, 1965; Adeleye, 1975; Kogbe, 1976; Dessauvagie, 1975; Petters, 1978; Offodile, 1980; Whiteman, 1982; Benkhelil, 1989; Okosun, 1992; Guiraud, 1993; Akande et al., 1998; Zaborski et al., 1998; Jauro et al., 2007; Obaje, 2009; Nwajide, 2013

Lithology and Thickness

Zurak Fm: It is made up of fine to medium, moderately well sorted feldspathic sandstone within thin shales. Thickness is not for certain known.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

Overlies the Keana Fm

Upper contact

Underlies the Makurdi Fm

Regional extent

Benue Trough Central . Equivalent of the Yolde Fm and Pindiga Fm in the Upper Benue Trough.

GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[8.4,8.5],[8.6,7.1],[8.9,7.2],[8.7,7.5],[9.4,7.5],[11.1,8.8],[10.7,9.2],[8.4,8.5]]]]}}

Fossils

Ammonites (Euomphaloceras septemseriatum, Hoplitoides ingens), Foraminifera, bivalves (Costagyraolis iponensis), Gastropods

Age

Middle Cretaceous. The four formations indicated in the Cenomanian through mid-Turonian interval are given quasi-equal durations here (Keana Fm = Early Cenomanian, Zurak Fm = Middle Cenomanian, Makurdi Fm = Late Cenomanian, and the Wukari Fm = lower Turonian)

Age Span:

Beginning stage:

Cenomanian

Fraction up in beginning stage:

0.3

Beginning date (Ma):

98.52

Ending stage:

Cenomanian

Fraction up in the ending stage:

0.7

Ending date (Ma):

95.88

Depositional setting

Marine depositional environment, specifically a shallow to moderately deep marine setting. The presence of organic-rich shales suggests periods of low oxygen levels, likely associated with restricted circulation or high productivity.

Depositional pattern:

Additional Information

Compiler:

Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024)- Stratigraphic Lexicon compiled from the following books:

Nigeria: Its Petroleum Geology, Resources and Potential, by Arthur Whiteman, 1982; (Volume 1) Published by Graham and Trotman Ltd.

A review of the Cretaceous System in Nigeria by P. M. Zaborski (1998) In Africa Geoscience Review, Vol.5, No.4, pp385-483

Geology and Mineral Resources of Nigeria by Nuhu George Obaje, Published by Springer-Verlag Berlin Heidelberg 2009; http://www.springer.com/series/772

Geology of Nigeria Sedimentary Basins, Nwajide C. S., 2013; Published by CSS Bookshops Limited, Lagos Nigeria.